A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section.
The high and low pressure turbines drive the corresponding high and low pressure compressors through inner and outer shafts. Some shaft configurations include multiple sections joined together utilizing an axial face coupling also referred to as a curvic coupling. A curvic coupling includes axially engaging teeth that provide alignment and power transmission. During operation, one side of each axially tooth is loaded and an opposing side is not loaded and therefore can result in leakage flow through the coupling. Leakage through the coupling is not desirable and therefore a seal may be utilized to prevent or slow leakage. However, such seals may not interfere with the coupling fit and therefore may not be loaded in all operational conditions.
Accordingly, although current seals provide some protection to airflow through the curvic joint, engine manufacturers continue to seek further improvements to engine performance including improvements to thermal, transfer and propulsive efficiencies.